1. Field of the Invention
This invention relates to a jacking device of the type which is generally known as a scissors jack.
2. Description of the Prior Art
There is known a jacking device which comprises a pair of vertically stretchable jack components lying in parallel to each other and each having a bottom supported in a floor pit, a mechanism associated with the jack components for stretching and folding them together, and a table supported on the jack components for carrying a cargo thereon. The jack components are foldable into the pit when the device is not used, and the table covers the pit when the jack components have been folded. The table is raised as the jack components are stretched.
The known device has a number of problems which occur as a result of the raising of the table. When the table is raised, it opens the pit. The pit is usually left open, or a separate cover is placed over the pit by the operator of the jacking device if he considers it necessary or desirable to ensure his safety during the jacking operation.
If the pit is left open, there is every likelihood that the operator may fall into the pit and get injured, or may drop a tool or anything else into the pit. If he forgets to pick up any tool or the like that he has dropped into the pit, it is very likely to cause some kind of trouble to the jacking device when the jack components have been folded. The use of a separate cover is an effective solution to any such problem, but the operator usually does not like to take the trouble to place the cover over the pit.